Hello, everybody.
I have been using FTE for as long as I have had my truck and it has helped me with many of the difficulties I have had with my truck; however, there is one issue with my truck that has yet to have found its match, and therefore, I have created an account to find a solution!
My 1973 F-250 Camper Special 390 V8 2WD sat in a tow yard for a year and 8 months. I found it, paid 450 dollars for it in a non running state, and fired it up a month after its removal. One thing I noticed almost immediately was a custom overhead cockpit style insert on the ceiling, with switches that do odd things and an 8 track and cassette player. But another thing I had noticed was the literal rat's nest of wires underneath the dashboard, where rats had been living and chewing through the wires behind the dash. Upon further inspection, I noticed that wires which should not go together have been spliced so that they do go together (eg. Red with Green, blue with black, black with white) in makeshift splicing jobs. As a result, (I think) none of the dash lights work, the gas gauge for the rear tank does not work, the tail lights do not work, the radio does not work, and finally, the blinkers do not work. The hazards do work though, which leads me to believe that the components behind the steering wheel work fine, it's just the wiring behind the dash that needs attention.
Thanks for reading!

 

Perhaps a new harness is in order. If you can't find a free wiring diagram somewhere, you may want to purchase one.

1973 Ford Truck Wiring Diagrams | eBay

 

Do you think it would be possible for me to just wire all of the wires back together?

 

Perhaps, but if the rodents have eaten the insulation that would have to be accommodated, and also all functions would have to be confirmed as reliably functional. Best wishes.

 

This is for a 74, but should help you out:

 

This helps a lot. Thanks!

 

The turn signal issue may not be a rodent problem. When the flashers work but the turn signals or brake lights don't, the problem could be in the column. I had this problem with my turn signals in my 77 f-150 recently. I installed a turn signal repair cam, with success. https://shop.advanceautoparts.com/p/...Fc2Xfgod9ZALVQ
You have to trim two of the "wiskers" on the repair cam so it will work freely.
There is a diagnostic thread on this forum for turn signal.

 

I also have had a rodent problem in my 04 f150. The dirty Rat chewed through my knock sensor wire. I had to remove the intake manifold to change the wiring.
However, two items to help prevent this:
1. It smells like jalapeno's
2. https://www.walgreens.com/store/c/na...d-5021a97696bf
dilute the oil 5 water to 1 oil and spray the solution near wire areas once a month. use logic identifing where to spray. The rodents don't like the smell.

 

I have found the use of Solder Sleeve Heat Shrink Butt Electrical Wire Crimp Terminal Connectors in tight areas a success. They solder and seal the wires quite well.
https://www.walmart.com/ip/50-Pcs-So...tors/251688944
I hope this helps, God bless
JD

 

oh okay. My brake lights do work, but not my tail lights. I may have found the solution to my dash lights problem, by wiring the wires that used to be together back together. Would this help?

 

That's it!!! You've identified it. Undoing all of the stupid things previous owners and varmints have done!
That's usually the first thing I do to a newly acquired vehicle, is to get all of the lights, and then everything electrical working.
I've seen a cut wire or two, but what confounds me is when I find connectors disconnected - sometimes with both ends right there!!!

 

So I started wiring things together, thinking I was doing a good job and proud of myself. Then, I hooked the battery up and the things that previously worked, my brake lights and hazards, quit working. There was also a time in which my tail lights mysteriously started working, but then weirdly stopped working. What a wiring disaster!

 

You'll likely find the same hack wiring in other places, too. Lots of tracing in your future!

 

You can verify by independently powering up whatever light or accessory you're working on, and then by probing the intended power source for voltage, with a test-light/automotive light bulb or with a voltage meter.
Beware of wires which are the same color, as colors got used in several circuits. The hash-marks and stripes can help, but can sometimes be difficult to see.

 

I apologize for miss understanding you earlier about your tail lights. I agree with checking one circuit at a time. refer to the schematics. Take a picture of what you are working with. The guys here have seen it all and can help in many ways. good luck.